A computing device, such as a personal computer or a network device, may include an operating system (OS) that provides an interface between hardware of the computing device and software processes that are executed by the computing device. The OS may particularly include a kernel, which may be a central component of the OS and may act as a bridge between the software processes and the actual data processing done at the hardware level.
Memory corruption occurs when the contents of a memory location are unintentionally modified due to programming errors. When the corrupted memory contents are used later in a computer program, it may lead to a program crash or unexpected program behavior. Memory corruption in a kernel is difficult to debug because the corruption could be from any code (including third party drivers) and it could affect different data areas during each run. Some debugging tools attempt to detect memory corruption at a point in time after the corruption has occurred (e.g., at the time of free( ) in FreeBSD), at which point the corrupting code context is lost. Other tools can detect memory corruption at the exact moment of corruption, but require a lot of memory (usually a memory page even for 16 byte allocations). This large memory requirement poses problems when trying to debug problems in scaled scenarios where there is insufficient free memory to allow for usage of such tools.